SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08172773a2739f54f835e1b34ad6943d57b925bcd8bebe03db7a0390cbb3b52e' 
  AND token = 'QAXhi7rv2TfGt2uZkXQU/5gzTpypFYY/OZ9fplIisNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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