SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afc787859e5a7360261046fe850db1ba917c4e6401073461f96c75c07ae5c6fd' 
  AND token = 'NNXTMKiL/eCnk28cMF8l0ebV0ajeVOwlJoK+/vSWTMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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