SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca8c23672f13252d813124ac03d347a09835f4646e6672f634b090e74616f5a' 
  AND token = 'OLTDPkr8E48en/c3FoTOqXy2nzUSGf9qP8mGEi1rnsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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