SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6081a18a7477eb699a9597388595dee1fcfe755f2bac64919fb9fb5a422aed53' 
  AND token = 'VmwViRr5NnrUjmeqH8/DNEIlD49bDjYVsLgvlqYIUXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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