SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9109af57acaddcd8091ffcb0650c550840a872288522b7740826cb9f93c4bd6' 
  AND token = 'Uh8wtXUiGKCygcKGDfnwviVdl4KMPG7u1IXUnmcoJBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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