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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e74b1b0af487f28ef935309530a288bddfd5a8d8d8841419fb007d3e69b5deb' 
  AND token = 'zYGudT15jCUovmM6+fB/7011stdxFoxJp/1E+07JVCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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