SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe3eca1e8134c3cb8f7a7c8780177cebb4ac8acd1f1fb7dfd25bee3d257bdc3' 
  AND token = 'E3esc0zHgUyKVqaTnVBDG2XPZbrWWvo6RKBs+PCIwr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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