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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331a2afcf0b51a88b3b551e1d334ab7eb4b3e3a588af4aa7b4c134ecfb74bcaf' 
  AND token = 'QJougbqarFrTaZyvoyG6gh1MnBjJmf86jRZJ3+PF1ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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