SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc909da972ab2be42ddbb4b62c4f173d67191aa87aacaecc1f41ce793fed1743' 
  AND token = 'TJb0SUqKTwNkh6Ir/F9oz6AuJu1/Z+tLcv9vGvzDzfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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