SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4773a5ca8e3f2b2d4decec11fe14484b5b76bbb06f108d05bb413530920217de' 
  AND token = 'wEDzQd4GblGr3h973PVrErDB8BBzGaLqAvL0Yx3unNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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