SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ab4e99793de73b4913b96dacf0ae42b7c2afc28ad56ee5b7413568d2f793968b' 
  AND token = '4MBwUE9pqAYwhKHf9D7GDZk5d0HrFILhu70gssyb88w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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