SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4761a31461571bd7e2caeb97af68116a6f44da42b8996c44b38059562ed32eb5' 
  AND token = 'XW/1tYLbrLd0tDnSGP7m5alulReUg6UHlMvVbnLFobM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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