SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4651904dbcd65ef4a1e88f95d44990965fbb26f67d955a2731191514e928b3ee' 
  AND token = 'Qcy3Sh/GxOdqCxQy70PjZ+Iiw4QbQwV1d7KjZ5fxZng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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