SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '340cc77271e69b3da5692b1b4680f2bd48cf372e5f99450a5aa82588cf9a841f' 
  AND token = 'GGIBUrW6n1kYoOF+Fm/wPjhmN9/ofR+7nDfTbS5dNHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}