Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81ef237706f5de238bcf11dbd3e917b71e7bb6876950e6ea81c21aeebca54b06' 
  AND token = 'x6HgejZIGcVEc0Fj5IFnEUnhrnPJZWBlZcDTMFjs+jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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