SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6129e889c3d1204797748118ede50302c1eb4b5159072b3f790b569266f20c4c' 
  AND token = '92yia5qAS9L+7+VnMJ+jdA/zWTvejqiKjjbB+QCShu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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