Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd575eedfd6cc6b09e71c4a5a89139f92af7f0c2e3a86dfce13a1bf37489b8561' 
  AND token = 'h9BaWI7t9k1iytl9oQ+qQH5xVWz+2EnJSAoZzgD+DOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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