SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '775c47497e969e01fc41ce947b95d7913d9ecbd1795e2e91e18956c2d7a0574f' 
  AND token = 'eP009KNNIo5HE2MgD5LA0bijV8pJoQ0mtu4asSVTf6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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