SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f84ab9a9153a13d055727f22ef961871d1341564c40f6c1407acd76821737b9' 
  AND token = 'xgspXQX4tZH49czu+j3I/SGFThY2hRoWJstg8TZYnXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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