SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2fd1a41dd15e62aa690b3e2979886c9128943986177099dbf5d6f7f50cf25f2' 
  AND token = 'qbz5U6PdkDwhC8gecwclqKCnvZKNzhtjWsEu5gRSj7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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