SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daccad064a3c87cd8b0d584c318564cc623267f3d526c30d8b42469179b477d3' 
  AND token = 'MBqGoCPapEDTTfd40qOZzRnlnDmXtwfyE0fwHDPBdHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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