SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934d25d63342646b3dc300e475dc54e53df81eb7d3b072bf831a8772c9449caf' 
  AND token = 'nqQw9gCtih+1yTaji+E8nxzaIN4Pp++6fX8wPlKg6vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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