SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598206238120e606770fc572307e4aa87f8c3d7b60ca629f2dfd72b8f5e97a29' 
  AND token = 'vAX++xGGkjJjJiEMWeDMRRd6GU2IVb8eI4Cm1VsiCXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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