SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3e5781127a07bf0bdcd7a85855536783ad8dcd2167b66490562b6b675ed31b6' 
  AND token = 'd0r05YfgGcodHx5hnD8adtS5ExrjrGp+CRfKfyqZYIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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