SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '251247d3a448735bc92cc8ca96aed33ced4d8c614d2f05875be2daea37509161' 
  AND token = '98CrUseKT/HIjA8yolUsLTnqIDu0m0B/b2lurw6+J/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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