SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '154ed2acc0af1434b0a4db0e8678872331d34c69ebad98fdcf3443fdbc5b1dde' 
  AND token = 'nKhQpZg+rAQun79cX0262PPuMkQukupOr2hrN7JHhdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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