Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6237b0dc09d0e6b1828defedc9ac03ee44b051d0ec70222a56a55afc48871398' 
  AND token = 'gC4bPjOCBxr+ziYJEvAENnitDI9oxQXOiYwqtcHBkIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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