SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4ffb8129ed152649e0ba71f8a22fc088a770e6a233ba82d6d707e363f594141' 
  AND token = 'vnIuKLZVNXinOfPunt/NwRBZ2F357KnOC31wJlgB5ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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