SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a11c64d924566cccf3c592c821fe21215ef0903f982642eb2f54998b3b4151c' 
  AND token = 'd4jlPvkBmttHHU/vuEOUgRptxoklaGPWGXUQB1b9KM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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