SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8313cb05928bfdbbe262bb20b9b9ad3cd8b103a026a53bf083b50ebec8c01609' 
  AND token = 'dyCmEa363XaIt5e67mNo1xAeCyqg6cFiqRpLcOSLycE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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