SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2b1b2a609d51c471783b3d74da5a8fbe536c7f3ce2164ae136f81495cf1926a' 
  AND token = 'MqB+SGucXyfgwm9hOi8WjOvC3VEsF4LN1HOrWHLe+l0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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