SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c638f40d6beb9178bd8f2b02d37ef5608458c8ba15bb80f49736cd4099e59b50' 
  AND token = 'KFsHV4BQ6X6UXeBAylTpN1ywUZLx2ZKHzgGZdarOrqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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