SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '349629ecc2386a9f47c44eefc14fd969bae4d10696c0950483934c595b78d60b' 
  AND token = 'NOzQKEkTT/OevA/LKABcn2MymOl26MtJlUSpwEpJ548=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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