SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd0c29f4f46256f1a238073d0e162c10f801598585432b0492f86d903be198a' 
  AND token = 'OG5B/7FNS6HQoG37f1uIeK4SKPxdXeVofQRA81u7x8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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