SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '580a59045163ea2ad97354a279e076f6b70f75218f2544f0d759366a09db46ef' 
  AND token = '8DCZBZmBcJh/keBtzLWhY+maxgRC+MHzxEr42wh9ATk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}