SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f4896b455dd93da80697234c1d70107ea8850550d2aa28941fb105621a338a6' 
  AND token = 'WQgGe0Hg5yy8pv+36VFZz8J2Ft1iChBHKUQ9jQwhczM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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