SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83bb0338cce52ceeb5f9d3ae0d667f76489a3070062f70f5b634c4c7bc0b3e2f' 
  AND token = 'SKsVxiXX+Owu4etZwFcxlZTfeu2iW0IXWcH+TRghR34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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