SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '966b8d81a577ba65c26f83cdb63acf3255db1e08d0d5c1d43b4033849f35b493' 
  AND token = 'bEkSbMsB/HpyFy9GZRWCz/phJjuXAAq5uVmNkY3zeP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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