SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad6ce74e7537e8b589076fc148f0dd652c3715626e8b00417a3e697ac487782' 
  AND token = 'yXjU+na+fEhOBXlxwUFIlLYKMrmQ+e9vHpRz0wKs+h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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