SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1fe817ce4e4fb24965963efd86bfecddc7b5615a3dc523ddd9d2863a6c92120' 
  AND token = 'CGn3W3oiwRB2qNzYvs/lJlU+rgVX3xQCJFEdIzg+7+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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