SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c9f953b5b8da1657dd3d100c436305b9d1d8b8171687c13cb8ed10e826ed33f' 
  AND token = 'ANZQ2eINlArOFonLrapup/imsmeTzOfDO7HXkXvkpPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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