SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e99b7efd80df7d960bf98e6511d3029024af99e587d06ec605d78b6daa644e2' 
  AND token = 'Br7ozLQOZrr2yp1FuH3IpgMfCzkJ/dRek8v6cCBLC1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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