SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d99af561b774945fa32373bff7249e339e5d90f978edc3b4272122f9a20deb0' 
  AND token = 'xQ47rMfFP0tWAryHWXsxlUTdLv2sqjL63rJTl7nBRkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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