SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '41c409a255e5052702a5355ea45a6b6f15cde9e60aef60c705a8ff69cffa3542' 
  AND token = 'iNn4qx7+3Kh/1oDJdxFlkZcOvjeJYfX5UsO6NVyqd2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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