SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a314e8ebe5321cefaf64f7849cfed3897c44c75d80aac03a1813c48abf2f36c6' 
  AND token = 'mOg43xOKjcjkwmlHByjfQQnpPnSYqG+S/uNJjfthYDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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