SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a211027d1da2da9f411bac2a1c3c5360c5350afb623c993c1501908956c33db' 
  AND token = '69Gb6xr5D8BfSTf0mxDdFE08wOZr9uFjnJhNlvaZuZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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