SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609d6a3179bc2a15c7673e89c18584162f0ed7b52c2471426215033a87f1d9a2' 
  AND token = '6XEAG6UgXcbskdBugPYlS1HGqZuK6zYoJTv+045ifTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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