SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f46e2a969e221a32c9d1c0da89f8c5218015e31316c1ab580027f359f93fb828' 
  AND token = 'jxGNzNWDt2Xsf710oBRBc4Hc+DXsPLCvgNKDlKBB+qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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