SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bb911f57e1bda60c7d86dedce474adc926685998867cd11c592cb8dce58a56b' 
  AND token = '5qHukaKBVCrbRhQMYTUnYKp1L3g90gR/ZvJlGwsGhZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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