SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e849ba05dc2f411ae1138fc55adf38cbd5216c3eb8c7336d9676894745890cb9' 
  AND token = 'GMxVYTVo4MvYXwIa5UjNDMmGxsLB6GBifk6sH1x9pSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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