SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bf5e571277b6f0a2dc0a05184800436a03fad832cd88a4f626c7abe6ea67223' 
  AND token = 'APJd7o4n+SNxLnFo74Xk1vbRAK2Gi2ZGOKFoqjwWrgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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