SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffd120f3a21a6b3b721d95377add43d374a4ea5fda4a4ea30904775bd9216c0' 
  AND token = 'nWhHcCt73IoPc40LUTvvIsQ6dDZUR5ZN3N9BqlOsXiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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