SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ca0cd4858a64e180a597b7b5d72352dda620fed10476de23f9247fce86bf578' 
  AND token = 'YpPosA8G3OW5UR6vLYtqVIh9+MZ75xq0oEJxH2F6QQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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