SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f6325257fd4500b9499893dda1dd38222a36e6a79fcfe1d412056c4445a7e09' 
  AND token = 'h42ba2AAOawhYn4v4xsuYaDOQhtUD9zniTMkcLhtbMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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