SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e56f7b4eea0926250b5819fb478d09853629b41efd4f7fd4db1ff916f6e025c2' 
  AND token = '6fKAodjLIV6bb8yjDb94FZSl9Uj7RhQxaOet1pBJ7ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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