SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4a716d72c1ea55b921345c17d81987be92f91aae2e935df367b8e9702f99fa1' 
  AND token = 'hI7V1prAxpmVEZX5KunZIxe0wckstnccchxkwESlsik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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