SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3fa9b0f6296f4f8b1573d9eefaf40920828cb9cfffce456a36652b11c74b754' 
  AND token = 'U9g/v+Mz/B7LdoTg06dYT+vKA9s+gDrep/+yd2TvPZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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