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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da9cf2b1cce6ab4fe9ce7e11118eb44f849c6fa6ebcbb4e79c595468d2d8de61' 
  AND token = 'IOBvYHSxklpqVKtCJrDonCl9qcit5dOrkxj81HsSkvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}