SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79dc5b29c58c0eeb01dfd45a7770487d98fd7956c99db261925b2ef0645bc245' 
  AND token = 'C9fp8wJAaMCei3E9cPFwFHueqXFcfxoUnARMAY0RwFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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