SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e76c4ad12fee51bd4d63a76237ae0145a3c99eeee1fd0a748f90a5bc27339e2' 
  AND token = 'YUldY5KPUPMpnYOIlJpWw9Qa7lZ3IQb3fItBZdGzszk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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