SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac238230e4a9ad5fdd6f9787754d4babaf53557892893ec552f858fadacd6b46' 
  AND token = '1cG1BkLEqnFebZCGfGWE9l/CtziCHsRmUKDnHkfEreM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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