SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd2fecf9e9b6e739386f9603aaf21f82b593139dfcc257b84d171a94fdbfb415' 
  AND token = 'RVglv0QKu6DV55/pJrQHX3mVrwn0S0UCaXESpyxfLl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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