SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd9801c99f54b1237a89f24e6f565d9092f1b086b4fc2b7fc5ae03cc5441e8f7c' 
  AND token = 'slUxHta+/WxgnV4uf7CyHjYy1QW2TYUD1erqTFmZpAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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