SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a72e5fd4a6aa853898222044b90348023e973e21fc5e07d281bdedff79daf9b' 
  AND token = 'CyVjybgQ9sp62h7zFOZGRlLPFDN+j9Z5UU/REezRA2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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