SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5af8fa857b35702e93f0066aefa9bbdd2d14393046c1c16369c07afe21d4c164' 
  AND token = 'AQtBJbskR4Faz8Y71I5L36NOAOUkU/6qouQqLQcIm14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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