SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4cbfab888cf7652d252992032c74ff3f14d77d92835ad716d24a26918815068' 
  AND token = 'jopkxeftvh0r8gg+MsB3JnKOHqaaLS26DZodccb3Bx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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