SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1ce26d100df67e401bf3f13088d156333668c32c0e3fc0571cdbc1def23428d' 
  AND token = 'lK9Aaz5WZpENAgqGI+VXmn1lvxcBDJEuLJ9tVr2j8nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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