SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bcdc3a7503883b72df460ccbead16c78caf5abec59dc6fcea8c2de718db8725' 
  AND token = 't3WeJzSEod8eaKXgGKooEj2Xqx4yhOOBtD12fNH9Y/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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