SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afff6f999fd55da5f9caedaf43e07ae30118d517a6b69825d5d265201b149416' 
  AND token = 'qR+FtnIjb8rk2tyJm2OosFqV/+doXLWk7H2ZuvBgLWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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