SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a993e2ceaf7f307dd5e78bc97376a106a86e7088f3b29031d5a40f1a4d94dd60' 
  AND token = '8lixcDf5/MVmOashcOCfWoX10o0QKEvQYzquB/hVGlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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