SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c2d70add2574cca4e68bc67ba47503fda6488418ab034c9e444dfd73ed4fbb' 
  AND token = '+SUtPpeHAjs8sBDsnaYwfD5waFBxBxP8VLhljwgdXMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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