SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7368a326dab77646850654080be3c79dcf00dbe818354f5ff869066292a4f279' 
  AND token = 'y9bCg8I7kfd2FpP7ipjmKuKYhneBkDWGLRZkncOn11A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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