SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ec725f64af38e2ecb5537854d3e633fe066dc79b989593516022280bdc1c430' 
  AND token = 'HZvFvgxZjtYX7XP0kld8GaozQP3de+w40ScFUOeKXd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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