SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b6e96f55e1955b666b755e15726805c0f2c00ffb5d6adc5f107b9888bafe0ce' 
  AND token = 'SudkSZc8rzQ4+FCmAG2d4+jQbhfO/F3M0/xNdaAkU1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}