SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7388a3768160fd01ff195e252da1ff30ba48f63ff1543e184f5cd12e984009b8' 
  AND token = 'NZNQo7CtdsuRXobtDMaZyzE6n5j5lGv32ojypNfI2+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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