SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e0705db41f86f7b2129caeb64a15f538b269035342d0e7aebb1754da18e2dba' 
  AND token = 'xYeexHGD565kRXYfgwGYHU8bukKFpTxXPWWviv4HmoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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