SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2baf83918f1f50eba60e1c30d6a066a094abb508611bc1eb283e02af9ac89a8e' 
  AND token = 'Lg6MWCQCAG8Y1f3/QmOv0AMKEnNya+Nj5Ix5dXBCAs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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