SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c8c1e15f9accd05780e75a0b018f716f23e495a90a79a778077c7c862790c9b' 
  AND token = 'dYLWMHKRqNVt7XHV7Q4Gr7LEzpJ4tqE8lPvhkz6nhJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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