SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7abfaae8faa08a99cc9005429ec6343ce449185bbc2352287a46a1d790f9f553' 
  AND token = 'fae0dmgpduv7I2NbIohJsDoSCDOSbmWfnRHkgT84j9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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