SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491c1329d3cce4275446c109d379f58affad6d6cee5a13657993a12f7682d697' 
  AND token = 'kCwukM2P6zV+hJCqgmr6+7YD/X18F2Va8mpmE9dhVUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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