SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1a74db96f2943d3fd7ac9cb42057ce304c86c0558c57e45b9804446ec6deee2' 
  AND token = 'a2wfoYEZsj9XPPghw+Q42SPG5vGBjZ6AmIfoBX1pWMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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