SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac2a2d07a8ca3d57e49cf85225e69262d89209b18cf6cf74d1e76b51afeedc31' 
  AND token = 'Szq9RDJl6LvM461qut/ShWRl2vs1I4R8hOLC9w7rGyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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