SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31627d87efae508dc18ed34df6edd6c71111b75f70ae9c440103aec74e72f6c7' 
  AND token = 'zHqn6TFSLS7KSCdYrDD/jDxFKQ/ajI9Ym0oQHDIxR2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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