SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b363d2e06fe504c9df27b04fff46bce2e03ea3df8ab6d1fc94be7e343443b007' 
  AND token = 'Ta4un7GD28pMzTvYEm22wqdN5twyUF0bGKZxC9UaJ4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}