SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f888af84f2611530eaff4ce2af58ab44677681c59e547856724fe62cb1349714' 
  AND token = 'zx/aPlWRZeevRpigknYiRzwRaL2VrYTyH+RxVxomgV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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