SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9357141070c4e937c201b3075d73abf8ecea3250b437ee7686871d7e44bd49a3' 
  AND token = 'YujOCtXEJQYLTS6I3h9C4KpiMHVanzLmC8gxR+zM/KY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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