SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8195c3effb14aa9408833a30a5aff85146fb8c95c3c5aae689697632af5fc488' 
  AND token = 'e+klxjfIzfCZDRA0Swnar8FnqudasEqw5I9hS1kjnlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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