SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '060d1ae3fc6a3be8409e33fbeb246b1d0838bd94ad88ff09cf426cf1d2ea2f7b' 
  AND token = 'LjzgHE3tbwOY5SZZ+w+awGwDlSG4iDWnY7jNCzRBL34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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