SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b048124461332efb42f9cc3c532d288daa8b1665b04a6f61b33749c181786b74' 
  AND token = 'oa7F/qBiJIXX/TQY2MjZgW2D1S54qmwqPSnXGpBwjto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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