SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '786883af6ad176ec690065a9072f7b9a9c29c89362b2ddf5b4eb4e5e9ff3e6f6' 
  AND token = 'RXwaGR+3VmUoJd5wmZXJtFJziz4p7zGCLUMpKHWtXyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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